Shouldn't be a problem to extend the wires. Or just replace them from the GTB board, they are designed to be replaced. Just be sure that no wires or solder crosses over between the tabs on the GTB. And if adding to the wires, or adding connectors use heat shrink tubing to protect any bare wiring.

Connectors are OK, be sure to use good quality ones, an keep an eye on them. Get in the habit of looking for any loosening or lack of solid connection each time you use them.